|Year|Single|US Cashbox|US Hot 100|UK Singles|
|---|---|---|---|---|
|1969|"Rock & Roll Holiday"|—|—|—|
|1970|"Be-Bop Confidential"|—|—|—|
|1971|"Roadrunner"|—|—|—|
|1971|"That's Fine"|—|—|—|
|1972|"The Red Back Spider"|85|96|—|
|1973|"Let Your Yeah Be Yeah"|60|57|52|
|1973|"Smokin' in the Boys Room"|2|3|27|
|1974|"I'm The Leader Of The Gang"|26|48|—|
|1974|"Kings Of The Party"|31|31|—|
|1974|"I Got It Bad For You"|—|—|—|
|1977|"Lady (Put The Light On Me)"|44|46|—|
|1977|"The Martian Boogie"|45|59|—|
|1979|"Love Stealer"|—|—|—|

Question: what was the average number of weeks that "let your yeah be yeah" spent on all of the different charting systems?
Answer: 56